Improve: report errors with loading the profile (#6735)

<!-- Keep the title short & concise so anyone non-technical can
understand it,
     the title appears in PTB changelogs -->
#### Brief overview of PR changes/additions
Report any errors that happen while loading a profile
#### Motivation for adding to Mudlet
So if a profile is corrupted for whatever reason (ie, computer crash) -
folks will have a better experience understanding what's going on and
how can they address it
#### Other info (issues closed, discussion etc)
The one rare case of a `TODO` in the codebase actually being fixed :O

src/TMap.cpp

@@ -2577,7 +2577,7 @@ bool TMap::readXmlMapFile(QFile& file, QString* errMsg)
     mapClear();
 
     XMLimport reader(pHost);
-    bool result = reader.importPackage(&file);
+    auto [success, message] = reader.importPackage(&file);
 
     if (!mpMapper.isNull() && mpMapper->mp2dMap) {
         // probably not needed for the download but might be
@@ -2586,12 +2586,18 @@ bool TMap::readXmlMapFile(QFile& file, QString* errMsg)
         // No need to call audit() as XMLimport::importPackage() does it!
         // audit() produces the successful ending [ OK ] message...!
         mpMapper->updateAreaComboBox();
-        if (result) {
+        if (success) {
             mpMapper->resetAreaComboBoxToPlayerRoomArea();
+        } else {
+            // Failed...
+            if (errMsg) {
+                *errMsg = tr("loadMap: failure to import XML map file, further information may be available\n"
+                             "in main console!");
+            }
         }
     }
 
-    if (!result && errMsg) {
+    if (!success && errMsg) {
         *errMsg = tr("loadMap: failure to import XML map file, further information may be available\n"
                      "in main console!");
     }
@@ -2606,7 +2612,7 @@ bool TMap::readXmlMapFile(QFile& file, QString* errMsg)
          mpMapper->show();
     }
 
-    return result;
+    return success;
 }
 
 void TMap::slot_setDownloadProgress(qint64 got, qint64 total)

src/XMLimport.cpp

@@ -60,7 +60,7 @@ XMLimport::XMLimport(Host* pH)
 {
 }
 
-bool XMLimport::importPackage(QFile* pfile, QString packName, int moduleFlag, QString* pVersionString)
+std::pair<bool, QString> XMLimport::importPackage(QFile* pfile, QString packName, int moduleFlag, QString* pVersionString)
 {
     mPackageName = packName;
     setDevice(pfile);
@@ -169,7 +169,7 @@ bool XMLimport::importPackage(QFile* pfile, QString packName, int moduleFlag, QS
                                          "and this one cannot read it, you need a newer Mudlet!")
                                               .arg(pfile->fileName(), versionString);
                     mpHost->postMessage(moanMsg);
-                    return false;
+                    return {false, moanMsg};
                 }
 
                 readPackage();
@@ -227,7 +227,7 @@ bool XMLimport::importPackage(QFile* pfile, QString packName, int moduleFlag, QS
         }
     }
 
-    return !error();
+    return {!hasError(), errorString()};
 }
 
 // returns the type of item and ID of the first (root) element

src/XMLimport.h

@@ -54,7 +54,7 @@ class XMLimport : public QXmlStreamReader
 public:
     explicit XMLimport(Host*);
     virtual ~XMLimport() {}
-    bool importPackage(QFile*, QString packageName = QString(), int moduleFlag = 0, QString* pVersionString = nullptr);
+    std::pair<bool, QString> importPackage(QFile*, QString packageName = QString(), int moduleFlag = 0, QString* pVersionString = nullptr);
     std::pair<dlgTriggerEditor::EditorViewType, int> importFromClipboard();
 
 private:

src/dlgConnectionProfiles.cpp

@@ -1547,11 +1547,19 @@ void dlgConnectionProfiles::loadProfile(bool alsoConnect)
     if (entries.isEmpty()) {
         firstTimeLoad = true;
     } else {
-        QFile file(qsl("%1%2").arg(folder, profile_history->itemData(profile_history->currentIndex()).toString()));
+        QString fileName{qsl("%1%2").arg(folder, profile_history->itemData(profile_history->currentIndex()).toString())};
+        QFile file(fileName);
         file.open(QFile::ReadOnly | QFile::Text);
         XMLimport importer(pHost);
+
         qDebug() << "[LOADING PROFILE]:" << file.fileName();
-        importer.importPackage(&file, nullptr); // TODO: Missing false return value handler
+        if (auto [success, message] = importer.importPackage(&file, nullptr); !success) {
+            pHost->postMessage(tr("[ ERROR ] - Something went wrong loading your Mudlet profile and it could not be loaded.\n"
+                "Try loading an older version in 'Connect - Options - Profile history' or double-check that %1 looks correct.", "%1 is the filename").arg(fileName));
+
+            qDebug() << "dlgConnectionProfiles::loadProfile: ERROR loading" << fileName << "due to:" << message;
+        }
+
         pHost->refreshPackageFonts();
 
         // Is this a new profile created through 'copy profile (settings only)'? install default packages into it